vertebral column 1 Flashcards
vertebral column
- 24 mobile vertebrae – regional differences
- 23 intervertebral discs
- ligaments
- vertebral motion segments
vertebral column requirements
- Protection
- weight-bearing / force transmission
- mobility
how do these requirements vary in the different regions?
• how does the bone & joint structure differ between the
regions to meet these different requirements?
lower levels of mobility > change into stability
Spinal stability / mobility
Stability & mobility of the vertebral column results from interplay between the:
• vertebrae / joint structure and the
• neuromuscular system
the vertebral column motion segment
the superior vertebra moves on the inferior vertebra • 2 vertebrae • 1 intervertebral disc • 3 joints • Ligaments • Muscles • Nerves
gross mvm of vertebral column
flexion - superior vertebrae rotate and translate anterior
• extension
• lateral flexion
• axial rotation
vertebrae
anterior = interbody joint, intervertebral disc between 2 vertebral bodies
posterior - 2 zygapophoseal joints , processes and laminae
movements of the vertebral motion segment
3 x rotations (angular mvms) + 3 x translations (linear mvmts)
movements usually involve a combination of rotation and translation components
Typical vertebrae
Vertebral body = major weight bearing component (withstand compressive forces) Vertebral / neural arch = encloses vertebral foramen
Processes = muscle & ligament attachment &/or form joints with adjacent vertebrae
vertebral end plate
inside of vertebral body is hyline cartilage
- 2nd ossification centre which doesn’t increase bone length and site of anulus fibrosis attachment
Cervical vertebra:
small vertebral body
lateral / uncovertebral lips on body relatively large vertebral foramen transverse foramen (for vertebral artery)
anterior & posterior tubercles bifid spinous process Articular facets 45˚ to the transverse plane
thoracic vertebra:
medium sized body wedge shape: anterior v body height < posterior relatively small round vertebral foramen articular DEMIfacets on body articulate with ribs articular facets on transverse processes for ribs long, downward pointing spinous processes Articular facets almost in the coronal plane
lumbar vertebra:
large vertebral body for weight bearing
flat superior/inferior vertebral body
relatively small triangular vertebral foramen thick blunt spinous process
mammillary processes
accessory processes
Articular facets aligned almost in the sagittal plane
vertebral body in weight-bearing
The vertebral body is designed for withstanding compressive forces, It is unable to resist translation or rotational forces!
- withstranding compression: shell of cortical bone with horizontal and vertical trabecular internally which is filled with blood and bone marrow
vertebral body in weight-bearing struts
vertical are thickest
horizontal are smaller but supportive